Telephone system.



F. MFSLOUGH.

TELEPHONE SYSTEM. APPLICATION men luv 13. 1915.

Patented D6019, 1919.

hm 30 Q3 INVETOR.

ATE

trn-

earns ii FRANK M. stones, or ELYRIA, OHIO, ASSIGNOR, ZBY'MESNEassisnmnnrs, 'ro S'I'BOMBERG-CARLSON TELEPHONE MFG. 00., or noonnsrnn,NEW YORK, A

CORPORATION OF NEW YOBK.

TELEPHONE SYSTEM.

Specification of Letters Iatcnt.

Patented Dec. 9, 1919.

such as will enable others skilled in the art to which it appertains tomake and use the same. I 1

My invention relates to telephone systems,

and more particularly to systems in which the central station connectingcircuits are automatically broken when the conversation is terminated.

One of the objects of my invention is to provide means for interruptingthe central station circuit connections at both ends of said'connectionsand assignin the control of such means to one of the su scribers who hasbeen" conversing.

Another object of my invention is to provide means to prevent theoperation of the line lamp of the other subscriber during the timeintervening between the hanging up of the receivers of the twosubscribers.

Another-object of my invention is to pro vide means for maintaining theinterruption of the central station circuit connections at each endthereof between the retirement of the subscribers and the retirement ofthe embodiment of my invention illustrated therein, at A is shownatelephone line to which a substation B is connected. At D is shown themain station provided with suitable means for connecting telephone linestogether, sac-.1 as a cord circuit C. A second line is Shown at E towhich are connected substations F, F F and F Either of the lines may besingle or multi-party lines, and

each leads to the station D. Hereafter the line A will be spoken of asthe calling line and the line E as the called line and the subscriber Bas the calling subscriber and the subscriber F as the called subscriber.able switching means are provided for connecting the circuit C to thetelephone lines, here shown as plugs and jacks, the line'A beingprovided with a jack J and the line E being provided with a jack J,. Thecord circuit terminates in the plugs? and P constituting portions ofsaid switching means. Suitable means are provided for signaling theoperator "from the substations, consisting of line lamps L and Lassociated respectively with the calling and called line. These linelamps are controlled respectively by the relays S and S Cutoff relays Sand S are also provided. The central station operator is provided with atelephone set, shown at T, which includes a receiver T and a transmitterT The connection of this set to the cord circuit is controlled by therelays R and R A test circuit is provided controlled by the'marginalrelay 8,. Suitable sources of ringing current M, M M and M are employed,each adapted to supply current of a particular characteristic.Commutators N, N N and N, may be provided for breaking the ringing upinto silent and active periods. Ringing keys K, K K and K associatedwith a master key K, are provided. A relay R, controls'the connection ofthe ringing current to the line E, and the relay-R is employed tocontrol the disconnection of the same. Subscriber controlled relays areshown at R, and R The relays employed to interrupt the strands of thecentral station circuit connections, or where a cord cir- Suitx cuit isemployed, to disconnect the plugs illustrated as a thermal arrangement,preferably made by connecting together two bars of metal havingdifferent characteristics, one

of which expands faster than the other, causing bar Y to bow downward,as shown in the drawing, with a slow movement.

'When the switching connection at G is operated, the relay R will beoperated, and

50 l part of the subscriber F to institute a call,

i when the switching device H is operated,the

vIi. 5

relay R, will be operated. The relay 28,, will not be operated at thistime, however, because the relay R, has completed a shunt thereof. Afterthe called subscriber res sponds, the relay R, will be operated,completing a second shunt of the relay R In the form shown, the primarycontrol of the disconnect relays is assigned to the calling subscriber.When the calling subscriber hangs up, the relay R, will be deenergizedand the first mentioned shunt to the relay R, will be broken. Atthe sametime, circuits will be completed through the relay R and through thedevice-X. The relay R will operate, disconnecting the plug P from thecord circuit and closing contacts in the circuit of the relay R When thecircuit is completed through X it begins slowly to operate, approachingthe switches 131 and 116.

After a little while, the device X will complete the circuit of therelay 3,, which will pull up its armature and complete a circuit for therelay R which, when operated, will disconnect the plug P, from the cord,com pleting the disconnection. The energization of the relay It,interrupts the circuit of the device X, so that it will be restored tonormal and the system will stand ready for the Withdrawal of the plugsand both lines be released for other calls. If the relay R had failed tooperate for any reason, the continued action of the device X, breaks thesecond shunt about the relay R which will operate over a circuitincluding relays R and S The relay R, will then complete a circuit forthe relay R and cause the disconnection of the plug P from the cord.

It will thusbe seen that the disconnection of both ends'of the cord andthe release of both lines is effected by oneof the subscribers, in theembodiment illustrated, by the calling subscriber. If, however, thedisconnection at both ends was eflected instantaneously and the calledsubscriber did not hang up as soon as the calling subscriber, the linelamp L of the called line would come back and the operator seeing thesame, would answer the call before the subscriber F retired, when therewas no desire on the thus causing the operator unnecessary work, anddelay the operation of the whole system. ,Howevcr, as the-device X isslow actmg, an interval of time is provided between the disconnection ofthe two plugs, which can be made of any suitable length and sui?'ficient for all practical purposes to give the subscriber at? time tohang up. If, in the operation of the system, the subscriber at l hangsup first, the second shunt about the relay it, will be broken. and whenthe subscriber at B hangs up, the first shunt about the same will bebroken, so that immediately when the subscriber B hangs up, thedisconenergizingthe relay 3w talk with the subscriber F, the receiver 1is removed from the switch-hook 2, which rises and closes a switch 2-3.A circuit'i's then completed for the relays as follows:

ground 4, battery 5S -67-8ltransmitter 93-2-1011*-12 13.- The relay S isenergized, pulling up the armature 14 and closing the switch 1415,and-completing a circuit through the'line lamp L, including the battery5 and to ground at th conductor 16., The lamp L is so positioned thatits illumination will be observed by the operator at the station D, whois ap prised thereby that a'subscriber on the line A desires aconnection. The operator then' iro'nnects her circuit connections withthe ineA by operat :the switching device G. In the forni ls i i tl ivn,the plug P is insorted into the jack J, the contacts 21-22 and 23 of theplug P registering res ectively with the contacts 18-19 and 20 of Acircuit will be completed through the/relay R, as follows: ground"2fl-battery,25relay R,-conductor 26 1ecpi3itacts 2l-28'contacts 23 and20re'l'ay,-.Sto ground 13, disconnects, the lampL and relay S r the lineby opening the switches 6-7 and 11-12. The relay R, will be energized,closing the switches 29 and 30 and connecting the operators telephone Tto the cord circuit, through the conductors 31 and 32. The relay R, willalso be energized over the following circuit from battery 33conductor34-upper winding if R,lconductor 35-conductor ide -switch 37 contact21over the line Athrough the talking set at B-back through the contzlcts19-22-conductor 3S) switch 40conductor 41'the other winding of therelay'R,back to the battery 33.' The rclaylt will close the switches 42and 43-44, but opening the switch 43-45.

at 51. S, will b operated. disconnecting the lamp L, and the relay 3,,from the line E by opening the switches 52 and 53. The relay R, Wlllopen a switch 54 in the circuit of i sea-pee thetcst magnet S and willclose a switch The relay R, will now be actuated over thefollowingcircuit: ground 56battery 57-switch 55-conductor 58conductor 59R 'toground at 60. R, will be energized, disconnecting the set T from thecord by opening the switches 61, and 62. A circuit will also becompleted when the switching device H is operated for the relayR asfollows: ground at 56-57R;,63R 48i7-S,4-.6. The relay R howe' 'yer, willnot be energized at this time because a shunt of the same has beencompleted, as follows:

generator adapted to operate the bell 66,

which we will hereassume to be the generator M. At thesaine time thatthe key K is operated, the master key K,- will be momentarily operatedby some suitable means -associating the same, which are well known andunderstood, and therefore, not illustrated here. The closing of theswitch K, completes a circuit for the relay R as follows: 67K,68-switch69conduc tor 70-R,- 71-switch- 72-conductor 7 3 switch 4443eonductor 7458-:-55-57- to ground 56. R, will be energized, closing the switches 75and 76-47 and opening the switclu777 8, the latter in the circuit of thetest relay S The closing of the switches 7 5 and 76-77 completed theringing circuit which is as follows: ground 79-battery 80-switch-75conductx)r 81-82 8 .-contact 85- 88-contact 8990-conductor 91-switch92-conductor 93-switch 77--76relay 3%,, switch K .comrnutator N ringingmachine Iii-rt) ground 9%. The commutator will periodically interruptthe flow of ringing current, operating the bell at intervals. The flowof current over this circuit through the bell'bridge 66 will not causethe operation of the relay R However, when the subscriber rcsp'ondsvthere:

ceiver- 95 will be removed from the hook-' switch 96, which will close aswitch9697, substitutinga circuit including the receiver and transmitterat the called station for the bell bridge, whereupon the flow of currentin the ringing circuit will cause the actua- [ion of the relay Rbreaking the circuit of the-relay It, at the switch 69 and calls-' ingthe deenergization of the relay R whereupon th ringing connections arerc-' stored to normal.

When the relay R, was energized, it also closed a switch 98,con'lpleting a locking circuit for-the said relay over the conductor 99to ground at 100. When the called subscriber responds, the relay R, Wlllbe actuated over the following. circuit :-conductor 10lupper winding R--.conductor l03-switch 104 conductor 105-sw1tch T778conductorfill-switch 92 conduc tor ill-contact 90'ovcr the line E to con tact85switch 83c0nductor 82.conductor 110conductor 111through the lowerwinding of li -to battery'lll. This relay will be operated, opening theswitch 72 in the circuit of the relay R, and closing switch 113,completing a second shunt about the relay R ns follows: from ground at1l4-battery 115switch l16-conductor 117switch ll3-conductor 50. "Withthe apparatus in this condition the conversationtakes'place between thesubscribers, At the termination of the conversation, assuming that thesubscriber at B retires first, hanging up his receiver and breaking theswitch 23 in the circuit of the relay R previously described, thearmatures and switches controlled thereby will be restored to thecondition illustrated in the drawing, breaking the first shunt about therelay R, at the switch 42 and completing a circuit for the relay R, asfollows: ground.l26

relay R-conductor 121switch -43-' conductor 7i-conductor 58s wit'ch 55,-battery 57-120 ground 56. The relay B will I be energized, disconnectingthe plug Efrem the strands of the cord circuit by opening the switches37 and 40, interruptin the circuit of. the relay R, and the cut-o clay Sat 27, thereby releasing the line A, which will immediately beavailablet'for other calls. The relay R- Will also close a switch 28 inthe circuit of the relay R which will, however still be open elsewhere.When the re-' lay 1 was denergized, a circuit was also completed throughthe device X, as follows: ground 100-switch 122-device X-c0n-, ductor130-switeh 454i -conductors 74 and 58-switch -battery tiff-etc ground56. The device X begins to operate in the manner described, andifallowed to conglihQCOl'd, thereby enabling the device X to return tonormal, and releasing. the called lme for immediate use, in the samemanner tinue to do so, will first close the switch 'as described inconnection with' the release of the calling line. device R failed tooperate, the device X would continue, and break the switch 116 in thesecond shunt of the relay R which .now being unshunted, would operateover its circuit including the relays R and S which has been previouslydescribed. This relay would close a switch 150, completing a circuitthrough the relay R including the battery I 57 and cause thedisconnection n the same manner as previously described.

- If the subscriber at F hangs up before the subscriber at B, thepreviously described circuit of the relay R, will be broken and thesecond described shunt of therelay It will be broken at the switch 113,so that when the calling subscriber hangs up and the first describedshunt of this relay is broken at 42, the relay R, will be unshunted andwill be operated, causing the disconnection as described, or, if duringthe interval of time between the beginning of the operation of thedevice X and the closing of the switch 131, the called subscriber hangsup, this same operation will take place. If at any time the device Rfails to operate, the device R will operate as described, causing thedisconnection. The disconnection having thus been made, is maintained byeither or both of the relays R and R as each of the relays R and It isprovided with a circuit controlled by each of the relays R and 13,. Therelay R controls the relay It,-

through the switch 150 and the relay K through the switch 201. The relayR controls the relay R through the switch 140 and the relay R throughthe switch 200. As the relay R is controlled by the switch v sistance towhich the relays R or R are wound preventsthe associated lines testingbusy by the operator of any marginal test relay, as S of any testingoperator. Either relay R or R will complete a circuit for the relay It,so as to maintain the same energized until the cord ,is restored tonormal. These circuits will be over the conductor 58-'one of theswitches 200 or 201 to battery 57, thus preventing the connection of theoperators set '1 to the strands of the cord circuit after the relay R isdeenergized.

It will be understood that any suitable form of. slow acting device maybe used at If for any reason the X. l have illustrated a thermal devicewhich is o erated by the heat from the coil Z, mainly ecause it isconvenient to show it in the drawing, the object being to provide somemeans which will delay the disconneca tion of the end of the cordassociated. with the called line and the release of the called line, soas to give the subscriber at F ample time to hang up. In fact, I do not.wish to be limited to the details or the embodiment 7 5 of my inventionwhich I have illustrated for the purpose of better, describing theinvention,, as it will be apparent that many departures may bemade fromboth the form and the details 0 this embodiment, without departing fromhe spirit of the invention.

I claim: 1

1. In a manual telephone system,-the combination of a main station,telephone lines leading to the main station, a substation on each line,line signal devices at the main station controlled from the substationsover said telephone lines, said devices being removed from such controlduring the conversational period, conductors at the main station forconnecting the lines together, a switch for connecting said conductorsto one of said lines, a second switch for connecting said conductorstothe other of said lines, mechanism at the main station fordisconnecting said conductors from one of said switches, mechanism atthe main station for' disconnecting said conductors from the other ofsaid switches, and means controlled by the switch hook of one of saidsubscribers for successively causing the actuating of said disconnectingmechanisms and releasing saidline signal devices.

2. In a telephone system, the combination of a main station, telephonelines leading to the main station, a substation on each line, linesignal devices at the main station controlled from the substations oversaid telephone lines, said devices being removed from such controlduring the conversational period, conductors at the main station forconnecting the lines together, a switch for connecting said conductorsto one line, a second switch for connecting said conductors to the otherline, mechanism for disconnec'ting the switches from the conductors, theline signal device of thecalling line being released when the switchthereat is disconnected, means at one of the substations controllingsaid disconnect mechanism and apparatus for delaying, an appreciableperiod of time, the disconnection of one of said switches from saidconductors until after the disconnection of the other has taken place.

3. In a manual telephone system, the com- 125.

bination of a main station, telephone lines leading to the main station,a substation on eachline, line signal devices at the fi'iain Sta-' tioncontrolled from the substations oversaid telephbne lines said devicesbeing re- 13() near-pee moved from such control during the convex"sational period, cord circuit conductors at the main station forconnecting telephone lines together, a switch for connecting saidconductors to one line, a second switch for connecting said conductorsto the other line, mechanism for disconnecting the first named switchfrom said conductors, mechanism for disconnecting the second namedswitch from said conductors, means for operating said mechanisms, adevice at one of said substations controlling said mechanism operatingmeans, and apparatus at the main'station for delaying the operation ofone of said mechanisms until the other is operated.

4. In a manual telephone system, the combination of a main station,telephone lines leading to the main station, a substation on- ,eachline, a cord circuit at the main station for connecting the 'linestogether, a switch for connecting the cord to a telephone line, linesignal means at the main station associated with the calling line andcontrolled by the calling subscriber removed from such control when thecord is connected to the calling line, a second switch for connecting athe. cord to another telephone line, a relay for disconnecting the firstswitch from the cord'and releasing said line signal means, a 80 secondrelay for disconnectin the second switch from the cord, means oroperating said relays including a source of current and circuitconductors, apparatus controlling said means including a switch-hook atone 86 of said substations and apparatus for delaying, an appreciableperiod of time, the op eration of one of said relays until after theother relay has operated.

5. In a telephone system, the comblnation 40 of a main station,telephone lines leading to the main station, including a calling and acalled line, a substation on each line, a cord circuit at the mainstation for connecting the lines together, a switch including a plug andjack at each end of thecord for connecting the cord to the lines,automatic d1sconnect apparatus controlled by the'calllng subscriber fordisconnecting the plugs from the cord and means to cause the actuationthereof automatically when the callingsubscriber retires, and apparatusfor delaying for an appreciable predetermined period of time thedisconnection of the calling plug only froni'the cord when the callinsubscriber retires before the called subscri er.

6. In a manual telephone system, the combination of a main station, a.calling and a called line extending to the main station, a substation oneach line, cord conductors at the main station for connecting the linestogether, a switch for connecting the conductors to the calling line anda second switch 7 "For connecting the conductors to the called tine,means controlled by one of sand subs-cr ibers for automaticallydisconnecting the? switches from the conductors when such subscriberretires, and means for delaying the disconnection of the switchassociated -with the called line from said-conductors when the callingsubscriber retires before the called subscriber.

7. In a telephone system, the combination of a main station, a callingline and a called line leading to the main station, a substation on eachline, a cord circuit at the main station for connecting the linestogether, a plug and jack switch for connecting the cord to the callingline, a second plug and jack switch for connecting the cord to thecalled line, a relay for disconnecting the first named switch from thecord, a circuit for said relay including a source of current, meanscontrolling said circuit for-causing the actuation of said relaygoverned'by the switch'hook at the calling substation and automaticallyactuated when the calling subscriber retires, a second relay controllingthe connection of the second switch with the cord, means for causing theactuation of the second relay and the disconnection of the second switchfrom the cord governed by the switch-hook at the calling station andmeans for delaying the operation of said second relay when the callingsubscriber retires before the called subscriber.

8. In a nianual telephone system, the 00111- Y bination of a mainstation, telephone lines leading to the main station, a subscriber oneach line, cord conductors at the main station for connecting telephonelines together, a plug on each end of the cord, means for disconnectingthe plugs from the cord conduvtors controlled from oneof saidsubstations and a slow-acting relay for delaying the disconnection ofone of said plugs until 'after the other has been disconnected.

9. In a manual telephone system, the combination of a main station,telephone lines leading to the main station, including a calling and acalled line, a subscriber on each line, cord conductors at the mainstation, a plug on each end of said conductors, means controlled by asubscriber for disconnecting from said conductors the plug connected tosuch subscribers line when the'subscriber rctires, and means controlledby the same subscriber for later disconnecting the other plug from saidcord conductors.

10. In a telephone system, the combination of a main station, telephonelines leading to the main station, substation devices including acircuit controller located on each telephone line and operable when thesubscriber thereat retires, apparatus at the main station for connectingthe lines together, ineluding circuit conductors and switches employingsleeve contacts, means for automatically interrupting said conductorswhen a subscriberuat one of the substations retires and electramagneticmechanism con- I trolled through the sleevecontact of each of saidswitches for maintaining said disconnection until the switches areoperated.

11. In a telephone system, the combinatlon of a main station, telephonelines leadlng to the main station, a cord at the main station forconnecting the lines together,

a plug and jack switch for connecting the cord to one line, a'secondplug and jacka relay for disconnecting the first name switch from thecord, a second relay for disconnecting the second named switch from thecord, a circuit for each of said relays, a third relay controllin eachof said circuits, a circuit for said t ird rela controlled by one ofsaid switches, a fourt relay controlling the circuits of the first and.second named relays and a circuit for said fourth relay controlled bythe other of said switches.

13. In a telephone system, the combination of telephone lines, a mainstation, a cord circuit at the main station for connecting telephonelines together, an answering switch for connecting tbe cord to atelephone line, a calling switch for connecting the cord to anothertelephone line, means controlled by the calling subscriber forautomatically disconnecting said switches from "said cords when thecalling subscriber retires, including a device for delaying thedisconnection of the answering switch from the cord while the callingsubscriber is on the line and means for automatically andinstantaneously disconnecting the callin switch from the cord as soon asthe calle subscriber has responded independently of said delayingdevice.

14. In a telephone system, the combination of a callingline and a calledline, a subscriber on each line, talking conductors for connecting saidlines together, a calling switch and an answering switch for connectingsaid conductors to said lines, means controlled by the callingsubscriber. for

' automatically and instantaneously disconnecting said conductors fromsaid switches when the calling subscriber retires and there isno calledsubscriber .on the called line, a

device for delaying the disconnecti u of the canin switch from thetalking conductors when the calling subscriber retires and a calledsubscriber is on the called line, and

connection of the calling switch from the talking conductors when thecalled subscrlber retires after the calling subscriber has retired andbefore 'the calling switch has .been disconnected from the conductors.15. In a telephone system, the combination of calling and calledtelephone lines, a substation on'each line, talking conductors forconnecting said lines together,- an

the talkconductors to the calling ineand a ca ling switch for connectingthe calling conductors to the called line, means controlled by thecalling subscriber for autoanswering switch for connectin means forinstantaneously causing the dismatically disconnecting the callingswitch from the talking conductors when the call ing subscriber retiresinstantaneously when there is no called subscriber on the called line,and means for delaying such disconnection when there is a calledsubscriber on the called line.

16. In a. telephone system, the combination of calling and'calledtelephone lines, talking conductors for connecting said lines together,switchesfor connecting the talking conductors to the telephone lines,means for automatically disconnecting said switches from said talkingconductors when one of said subscribers retires and thermalmeans fordelaying the disconnection of'one ofsaid switches from said talkingconductors.

17. In a telephone system, the combinef tion of telephone lines, linkconductors including talking strands for connecti said lines together,.aswitch to connect sai link conductors to a telephone line, mechanism fordisconnecting said switch from the t'a'k' ing strands andfor'interrupting said talk-- ing strands automatically operated when .asubscriber retires his talking set and ap paratus for delayin theautomatic operation of said mec anism for a predetermined andappreciable period oftimes 18. In a telephonelsystem, the combination oftelephone lines, link conductors ineluding talking strands for connectinsaid lines together, a switch to connect sai link conductors to atelephone line, mechanism for disconnecting said switch i'rom thetalking strands and for interrupting said talkin strands automaticalloperatedwhen a su scriber retires his tal ing'set and apparatus indeendent of said mechanism '-:for

mechanism for a predetermined and appreciable period of time. Ihavesigned my'name day of-May, 19 15. I

FRANK SLOUGH.

delaying t e automatic, operation of said hereto this 10th

